Reciprocating refrigeration compressor liquid slugging mechanism, hazard identification and anti-liquid hammer protection

Reciprocating refrigeration compressor liquid slugging mechanism, hazard identification and anti-liquid hammer protection

Liquid slugging happens when unevaporated liquid refrigerant or oil enters compressor cylinder; incompressible liquid will cause instant impact force, cracking valve plate and bending connecting rod. Even short liquid slugging lasting less than 2 seconds can permanently deform valve plates; continuous liquid impact may break connecting rod and lead to catastrophic unit failure. Xiteliduo reciprocating compressor installs liquid level sensor on suction accumulator and temperature sensor at suction port; suction superheat below 2K will trigger load reduction alarm. Small 4-cyl reciprocating refrigeration compressor liquid slugging mostly occurs after sudden defrosting; massive liquid refrigerant flows back from evaporator to compressor suction side. Medium 4-cyl reciprocating refrigeration compressor liquid carry-over may be caused by faulty expansion valve; oversized valve opening leads to insufficient refrigerant vaporization. Large 4-cyl reciprocating refrigeration compressor with long suction pipeline is prone to liquid accumulation in pipeline low points; liquid will surge into compressor during sudden load rise. Large 6-cyl reciprocating refrigeration compressor multi-cylinder structure means liquid slugging may only affect individual cylinder; partial cylinder damage is easy to be ignored in early stage. Many operators restart unit immediately after power recovery without checking suction state. This operation makes liquid slugging accident probability increase by 51%. Single-unit two-stage refrigeration compressor liquid slugging mostly appears on low-stage side; liquid entering low-stage cylinder will generate interstage liquid droplets impacting high-stage components. Cascade unit high-stage reciprocating refrigeration compressor has higher working temperature; liquid slugging here will produce rapid thermal shock and crack cylinder head material.

FAQ

Q1: What damage can short liquid slugging within 2 seconds bring to reciprocating compressor? A1: It can permanently deform the compressor valve plates. Q2: What protection threshold does Xiteliduo compressor set for suction superheat against liquid slugging? A2: Load reduction alarm is triggered when suction superheat drops below 2K. Q3: What operation condition easily causes liquid slugging on small 4-cyl reciprocating compressor? A3: Sudden defrosting leads to mass liquid refrigerant backflow. Q4: What fault of expansion valve will cause liquid carry-over for medium 4-cyl reciprocating compressor? A4: Excessively large valve opening results in incomplete refrigerant vaporization. Q5: Why is large 4-cyl reciprocating compressor vulnerable to liquid slugging when load rises suddenly? A5: Liquid accumulated at pipeline low points surges into compressor. Q6: What risk will happen if restarting compressor right after power recovery without inspection? A6: Liquid slugging accident probability increases by 51%. Q7: Where does liquid slugging usually occur for single-unit two-stage refrigeration compressor? A7: Liquid slugging mostly occurs on the low-stage compressor side.